Rotary magnetic damping systems are used in a number of applications, for example in applying a braking force to an actuator, for example in an aircraft system.
A rotary magnetic damping system typically comprises first and second elements which rotate relative to each other. One of the elements is magnetic, and the other of an electrically conductive material. The relative rotation of the elements induces eddy currents in the electrically conductive material which in turn generates a magnetic field. This magnetic field opposes the field of the magnet, such that a braking force is generated on the movable element.
In aircraft systems there has been a movement to powering actuators for operating various components, such as flight control surfaces, undercarriage components, thrust reversers and so on, electrically rather than hydraulically. This saves weight, which is beneficial in aircraft. Situations may occur, however where if there is a disconnect or failure between the drive motor and the actuated element, external forces acting on the activated element, for example gravity or aerodynamic forces, may cause the surface and the attached actuator to run away. Systems must be employed to absorb the energy of such a runaway situation.
It would be desirable to provide a rotary magnetic damper which may address this situation.